In facilities that contain numerous electric motors, the motors are typically supplied through a grouping of motor starters known as a motor control center, or “MCC.” Each motor starter is housed in an individual enclosure, referred to as a “bucket,” or “cell”. Multiple motor starters are then housed in a larger enclosure with a common power bus supplying the various motor starters. One of the features of a motor starter is a disconnect switch typically actuated by an operating switch located on the front of the bucket that can be used to de-energize the particular motor supplied by the motor starter. Another of the many benefits of a modern motor control center is that individual motor starters may be removed for maintenance, repair, or modification without the need to de-energize the entire motor control center.
Some motor control center units are equipped with a means of removing or “racking” the motor starter bucket from the energized bus of the MCC unit. One such embodiment utilizes a jackscrew that is accessed from a port on the face of the motor starter enclosure. A human operator typically inserts a tool to manually rotate the jackscrew.